Royal Opera Arcade
Building From 1816
Designed by John Nash, completed in 1816-18, considered to be London's oldest existing arcade having survived a fire, dereliction and the blitz. See Her Majesty's Theatre for the history of the building.
Although the entrances leading into the theatre from the arcade have long gone, the shops with their bow-fronted windows are still used as Nash intended. See English Buildings for a good post on this Arcade.